经典的金相组织照片(会员"leomet"的合集)

leomet

回复 281# 天涯海阁
You are reading the art works from one of the best, if not the best,  metallurgists in Taiwan.

leomet

Malleable iron is cast as White iron----- a metastable carbide (called Cementite) in a pearlitic matrix. Through an annealing heat treatment (high temp + long holding time) the Carbide is transformed: Carbon agglomerates into small  aggregates of graphite, leaving a matrix of ferrite + pearlite,  according to the exact heat history it goes thru.

leomet

QT 200
Beautiful photos taken yesterday.

leomet

It was aimmed at QT 500-12%, but  this is what was obtained: 710-8%.
Poor control of alloying elements from scrap steels. Too much Cr, Cu, Ni,
resulted in too much pearlite%, and thus, too high a tensile strength.

lmnxyz2004

不错的内容啊！

leomet

Macro photos for QT 200 in  #280 .
The one in the middle is 5 mm in thickness.
White areas are mostly Ferritic while dark areas are Pearlitic.
Chill effect from walls of green sand mold causes  undercooling of iron melt
and  produces D-type graphite which favors the formation of Ferrite.
As the degree of undercooling subsides inward, A-type graphite
makes its appearance, accompanied by the matrix of full Pearlite.
Left one: further inward, constitutional undercooling arises and some
D-type areas appeared again in the center.

leomet

AISI 1513, Q / T  Very fine grains.
Can you tell me how fine they are?
A ball park figure will be fine.

leomet

回复 289# 小一哥


     Good for you !
     It  should have broadened your horizons  staying in Taiwan for 6 months.

leomet

Photos that are feast to your eyes.
JIS S45C, normalized.

leomet

Laser welding, with and without filler metal.

snookitty

请问老师有做过铝合金5083的金相吗，我想看到晶粒大小，可是怎么也做不出来

leomet

M2 high speed steel : Q/T

Primary carbide dispersed in the matrix of tempered Martensite.

leomet

Feast to your eyes.
Pearlitic grey iron.

leomet

我台灣博客上的一篇貼文, 給外行人解釋"物理冶金".  A post  in my blog in Yahoo Taiwan.

物理冶金 所學何事? What is metallurgy?

冶, 陶冶, 改善/提昇之意;     金, 金屬.

冶金學 ,  改善提昇金屬性質性能的一門科學.

"物理"冶金學 乃運用"物理手段" (機械力: 鍛打鎚擊; 熱力: 加熱/冷卻) 來改善/提昇 金屬性質性能的一門科學.

**   Physical metallurgy is the study of the structure of metals and its influence on metal properties and performance.  
-urgy  =  science of ;        metal.lurgy(冶金) = science of metal = 金屬科學   metallurgist 金屬科學家

物理冶金(學)是一門科學, 專門探討金屬(微觀) 結構(microstructure 俗稱"金相組織")與它對金屬性質properties與性能performance的影響.

微觀結構的觀察需借助光學顯微鏡(可放大~1000x) 或電子顯微鏡(放大數十倍到十萬倍)

材料性質: 物理方面: 導電性 導磁性...   ;   化學方面: 耐蝕性....

           機械方面: 強度(靜態: 抗拉 抗壓 抗剪;  動態: 疲勞強度 耐衝擊性 )  韌性,   耐磨耗性....

* 從事與金屬加工有關行業的人, 如果有這些金屬科學的知識, 遇到問題時, 就可很快解決, 甚至事先就可防範這些問題的發生.  
現在是知識經濟的時代, 如果你的(工業)產品所應用到的工程知識越多, 通常其附加價值會越高.
你在金屬行業的薪資, 通常也是與你腦袋裡裝的冶金學知識成正比.

    相 變化  (phase transformation)   

1.  液相變固相 (即鑄造的 凝固過程, )  晶粒形狀, 大小, 分佈情形, 該如何操控?  以獲得所要 的性質/性能.

2.  固相間的變化 (熱處理 ) 操控晶粒內部"相"的形狀, 大小, 分佈情形, 以獲得所要 的性質            

   金屬晶粒內部的"相 phase" 一般分為"結合相"(binding phase)與"耐磨相"(hard phase), 兩者之間的比例 可支配材料的韌性與耐磨性

    (機械)性質來自於(金相)組織 , (金相)組織則由(化學)成份與熱履歷(heat history)來控制. 成份由材料的選用來決定. 熱履歷包括鑄造, 鍛造與熱處理過程.  搞懂這些後,  看著一個金相組織, 即可推斷出此金屬零件的過去---"熱履歷" (heat history) 與未來---預期的使用壽命(projected service life),  就像醫師看器官組織切片做診斷分析.

  材料破損原因分析   Failure Analysis

  研究金屬材料破壞/失效的機制,  知其原理後, 就可想辦法提昇機械性質, 增長使用壽命.  

  材料破裂後的破斷面紋路, 可看出應力大小, 破裂進行方向, 速度(驟裂? 緩裂?), 由此可找出破裂起源點, 找出破裂源點後, 再研究為何破裂由此處起始.  是設計上? 或製造上? 材料上? 還是熱處理問題? 有點像醫學上的"驗屍"工作.  有時候是兩三個因素 對材料的破裂都有"貢獻"---不是單一因素造成.

To be continued.

leomet

Beautiful photos of FT iron.
White eutectic appears because of poor inocculation treatment.

leomet

與冷模鋼 (例如SKD 11) 類似的"相"的配置. 2006年拍的.

第二相(耐磨相)的形貌(morphology) 攸關鋼材韌性的高低: 越圓渾, 越不易起裂, 韌性越高.

leomet

回复 308# wqf1981


出書? 工程浩大!  退休後再說吧. 因公司只有我一人, 現工作還很忙.

    我1984至今最精華的圖片都上了论壇, 看此論壇就夠了. 再者, 彩色印刷, 不如螢幕上照片漂亮.

leomet

SCM 415 carburized and chrome plated.
Note the thin copper plate beneath the Cr plate.

leomet

Hi Cr (25%) cast iron for abrasive blasting wheel blades.
As-quenched from 1040C.  Martensite in the matrix not tempered yet.
Carbide tinted in various colors. Carbide darkened so that
matrix can be seen more clearly. If untinted, reflection is too
strong and fine particles of carbide would be difficult to be seen.

leomet

Austempered Gray Iron,  AGI.     Floor 299 Austempered.
1020C x 300C
photo~487 to 597  tinted.
Austenized at 1020C ; quenched and held at 300C.
Microstructures are: graphite flakes + Bainite + Austenite islands.
The interweaving of Bainite with austenite (hard and tough phase)
makes this material wear-resistant, tough and much stronger than pearlitic gray iron.
But it is still weaker than ADI, as a matter of course.